ABSTRACT Apathy is a symptom that presents with a deficit of motivation, reduced goal-directed behaviors and responsiveness to environmental stimulation, and a flat mood. Nearly 50% of nursing home (NH) residents live with Alzheimer?s disease and related dementias (ADRD) and 84% of NH residents with ADRD demonstrate apathy. Apathy is a significant problem because it is associated with considerable negative outcomes, including accelerated cognitive and functional decline, lower quality of life, poorer illness outcomes, greater need for institutional care, and higher mortality. Caregiver-resident communication is fundamental for daily care activities in NHs and significantly impacts quality of care. Interacting with residents with ADRD can be challenging, due to their difficulty in understanding, remembering, and verbally expressing themselves. Interacting with residents with ADRD and apathy is especially challenging, because they are socially withdrawn, do not take initiative, and rely on others? prompts to engage in interactions. Interventions to improve caregiver communication and person-centered activities have been shown to reduce some behavioral symptoms in ADRD. It is unclear to what extent that apathy symptoms differ over time for the same individual and across different individuals. This information will help to clarify the potential extent to which apathy can be changed. This proposed study will address this gap by analyzing variations in the magnitude and duration of apathy symptoms within and between individuals. Further, it is unknown how caregiver communication impacts apathy. Thus, this study will examine the impact of caregiver communication on apathy. This is a secondary analysis using existing video data from a completed NIH-funded clinical trial. The dataset comprises video observations from 46 residents during caregiver-resident interactions in 12 NHs. Videos were recorded during routine care activities at multiple time points over 5-9 months. This study aims to examine variations in the magnitude and duration of apathy symptoms and examine the concurrent and sequential relationships between caregiver communication and apathy symptoms. First, we will test variations of apathy pattern across residents, within the same resident across interactions, and within each interaction. Next, we will analyze four aspects of caregiver communication qualities: 1) communication topic, 2) emotional tone, 3) person-centered verbal communication, and 4) person-centered non-verbal communication. We anticipate that person-centered communication approaches will be associated with lower levels of apathy symptoms. This is the first study examining the impact of caregiver communication on apathy. Findings will help identify approaches to improve caregiver communication, which can be used to develop interventions to reduce apathy, improve resident health outcomes, quality of life, and reduce mortality for NH residents with ADRD. This study will help promote care quality and efficiency for ADRD and achieve the major goal of the 2017 National Plan to Address Alzheimer?s Disease.